Abstract
Multiple regions in the human brain are selectively tuned to process particular categories of visual stimuli, such as scenes, objects, faces, and bodies. These category-selective areas likely have differential sensitivities to other visual features besides these superordinate categories. For example, scene-selective parahippocampal place area (PPA) and occipital place area (OPA) have been demonstrated to prefer distal stimuli, while object-selective lateral occipital complex (LOC) prefers proximal stimuli (Amit, Mehoudar, Trope, & Yovel, 2012). Here we explore whether these category-selective regions also show a general depth preference for locations either in front of or behind the point of focus. We presented participants with patches of random dot motion in different peripheral locations in a blocked fMRI design. Participants viewed the stimuli through red-green anaglyph glasses, such that we could stimulate a given 2D location at different depths (either in front of or behind fixation). Contrasting activation for these front and back locations, we found no depth preference in LOC or fusiform face area (FFA), and a significant front-preference in extrastriate body area (EBA) and motion sensitive area MT+. Interestingly, we found a significant back-preference in PPA and OPA, with non-significant trends in the same direction in retrosplenial cortex (RSC). This preference of scene-selective areas for stimuli behind fixation is consistent with the notion that real-world scene perception involves processing of background information which often appears behind the focus of attention.
Meeting abstract presented at VSS 2016